Those who have high hopes that reprogrammed adult stem cells are a way to bypass the sticky political issues associated with embryonic stem cell research, especially in the United States, might not be thrilled with a report in Technology Review about a puzzling number of genetic mutations in these cells. What's worse, some of these mutations have been linked to cancer.
While little is known about how these mutations would effect how the cells could be used in medicine, it does make researchers extra cautious as they develop reprogrammed adult cells into treatments. Of particular concern, according to the Technology Review article, is the fact that both cancer cells and stem cells continually divide.
The article mentions a couple of studies into the genome of induced pluripotent stem (iPS) cells, which are adult cells that have been reprogrammed into stem cells. They, in turn, could be transformed into any type of tissue. Researchers at the University of California, San Diego, sequenced the gene-coding portion of the genome in 22 iPS cell lines that had been reprogrammed. "Every cell line we looked at, we found single [genetic-letter] mutations in the protein-coding region, an average of six mutations per cell line," Zhang told Technology Review. A disproportionate number of the mutations appeared in genes involved in cell growth or in genes that have been previously linked to cancer.
In another study, researchers from Canada and Finland found the iPS cells contained more small deletions or duplications of DNA than either skin cells or embryonic stem cells.
The conclusion is that more study and caution need to be the order of the day as scientists learn more about how the cell reprogramming process is creating these potentially devastating changes.
- read the article in Technology Review